In the copending U.S. patent application 191,625, there is shown and described a garment having cuffs and having separate grounding paths. There is no wrist strap.
There are, in the field of static control garments, applications that require a wrist strap to be worn; for example, where a wrist strap is designated by the customer as the body contacting mechanism for a dual-path ground. Some companies require that the contact with the wrist strap be metal to the body. An example of the latter wrist strap is in the nature of a "Speidel" watchband. There are also fabric-type wrist straps that have two metal plates as conductive body-contact elements.
The stated metal-to-the-body requirement would be a difficult requirement to comply with in a garment, especially one made of a soft textile (fabric) material. The metal would have to be permanently attached to the fabric, and this means that the metal would be laundered under the same washing conditions required for laundering of the garment. The result could be a problem relative to metal deterioration caused by such factors as corrosion, or coating of the metal with an insulator. Build-up of insulator could be caused on the metal by soaps and washing chemicals.
Until now, a wrist strap having two isolated body contact points, and directly contacted to a dual-wire cord leading directly to the ground, has been the only way to satisfy the metal-to-the-body requirement in a redundant dual-path monitoring system. But direct connection from wrist strap to ground has at least one disadvantage, and at least one nonadvantage. The disadvantage is that the wrist is tethered-which can be an annoying and efficiency-reducing thing. The nonadvantage is that there is no "Faraday cage" (Faraday cage-like) action such as is described below.